The Story Continues Cliche is Suitable for Life

I think I am smart.  I worked hard for good grades in school.  I do great work at my job and with other opportunities in my life.  Many people tell me I am smart.  Of course, they mostly say this after I say that I am dumb.
Yes, this guy thinks he is smart but does not feel smart.  Many great examples can include me getting an A minus on a paper and breaking down, receiving a promotion and bonus and feeling more stressed, and another good example is this note. 
I found that envelope with my name on the outside of it in that dreadful mailbox.  Smart is just something I will still never feel because it seems more logical.  Already, the logical choice is completely gone as soon as I open the mailbox and see my own name.
I heard steps coming around the corner of the building.  Instead of just closing the mailbox door, I grabbed the envelope before closing and taking the key. 
The steps were getting louder.  My sense of time was messed up.  Clogged mind, clogged time.  Instead of running away, I just hid behind that corner.  Expecting some annnoyed person to arrive and start cursing that someone stole their mailbox key.   It appears my own thoughts were scurrying for negative events to happen.  The footsteps stopped right by where I was standing by the mailbox.
No one came around the corner. No one started to yell.  No one made any sounds.  My own heartbeat was in my throat.  The pounding of footsteps was now the veins on my temples pulsing deeply. 
It had to have been an hour before I moved.  My eyes bulging out of their sockets.  I wanted to see something move since my ears seemed to be failing at hearing anything other than my own bodily ticks.  To wait for even a short time expecting only one outcome of being caught, it seems like a trivial decision to move or stay.  I needed to breathe deeply to get past all this thought. 
Then, the logical thoughts came in after a few deep breaths.  Why was I even overreacting? Sure, I'm holding an envelope from a mysterious mailbox, but why would hearing footsteps of any nature make me want to hide?  I should just be causal.  That's who I am.
I walked away casually.  After I was a few feet from my building entrance, I decided to do the casual head turn.  Nothing fishy going on here.  Just going to crane my neck to take in my surroundings.  Sounds like a casual and boring thing. 
My head turned towards the mailboxes and eyes followed suit.  Standing there next to the mailboxes was a quick glimmer and then nothing else.  The glimmer was like those times you close your eyes real tight and start to see random colors flashing in the darkness.   This glimmer only lasted for a second. 
There was no one standing anywhere near the mailboxes.  Where did the steps come from or better yet, where did they go?  My mind might be creating situations.  This easily could be my imagination taking myself for a ride since something inconceivably rare just occurred. 
I ran into my building and up to my apartment.  I closed the door and should have enjoyed the silent darkness like I usually do.  It was all unnerving.
After getting in and trying to relax, I actually let go of the envelope.  Instead of opening it, I let it sit there on my counter.  Sometimes I need to shower to think.  No, I didn't smell.  I just believe better thinking comes from personal spaces. 
So, I put on my scuba suit (PG) and jumped in the shower. 
My mind went everywhere.  The only original thought was to open it since it was obviously addressed to me.  So, I got dressed and ran to open the letter, but the weird thing is, it was already open.  To be continued...